Generation of contact masks for inkjet printing on solar cell substrates
Granted: November 22, 2011
Patent Number:
8062693
A contact mask for inkjet printing on a solar cell substrate may be generated by creating a printing bitmap of contacts to be printed on the solar cell substrate. The contacts may be located on the solar cell substrate by mapping coordinates of the printing bitmap to coordinates of the solar cell substrate as positioned in the inkjet printer. The location of the contacts on the solar cell substrate may be defined relative to a location on the solar cell substrate, such as relative to…
Etching of solar cell materials
Granted: October 4, 2011
Patent Number:
8029683
A solar cell is fabricated by etching one or more of its layers without substantially etching another layer of the solar cell. In one embodiment, a copper layer in the solar cell is etched without substantially etching a topmost metallic layer comprising tin. For example, an etchant comprising sulfuric acid and hydrogen peroxide may be employed to etch the copper layer selective to the tin layer. A particular example of the aforementioned etchant is a Co-Bra Etch® etchant modified to…
Solar cell with reduced base diffusion area
Granted: August 30, 2011
Patent Number:
8008575
In one embodiment, a solar cell has base and emitter diffusion regions formed on the back side. The emitter diffusion region is configured to collect minority charge carriers in the solar cell, while the base diffusion region is configured to collect majority charge carriers. The emitter diffusion region may be a continuous region separating the base diffusion regions. Each of the base diffusion regions may have a reduced area to decrease minority charge carrier recombination losses…
Torque arm assembly and method
Granted: June 14, 2011
Patent Number:
7958886
A torque arm assembly, used with a solar collector mounted to a drive shaft, comprises a torque arm with first and second ends and a torque arm coupling assembly including a drive shaft enclosure defining an open-ended channel sized to house the drive shaft. The channel has a circumferentially extending substantially continuous drive surface between the ends that lies adjacent to the drive shaft so the drive shaft and the drive shaft enclosure rotate together. In some examples contiguous…
Flexible wind deflector for photovoltaic array perimeter assembly
Granted: June 7, 2011
Patent Number:
7956281
A photovoltaic (“PV”) array includes a plurality of interconnected PV modules. A PV array perimeter assembly may be positioned along the perimeter of the PV array to restrain horizontal movement of the array. For improved wind performance, the PV array perimeter assembly may include curbs that come with pre-attached flexible wind deflectors configured to prevent wind from penetrating underneath the PV array. The flexible wind deflectors may be made of a flexible membrane and may…
Solar cell and method of manufacture
Granted: March 1, 2011
Patent Number:
7897867
A solar cell that is readily manufactured using processing techniques which are less expensive than microelectronic circuit processing. In preferred embodiments, printing techniques are utilized in selectively forming masks for use in etching of silicon oxide and diffusing dopants and in forming metal contacts to diffused regions. In a preferred embodiment, p-doped regions and n-doped regions are alternately formed in a surface of the wafer through use of masking and etching techniques.…
Transient photoluminescence measurements
Granted: February 22, 2011
Patent Number:
7893409
A photoluminescence mapping system and method for use in fabricating solar cells that eliminates the need for complex and expensive light sources, filters and high sensitivity cameras. Generally, the method includes: (i) irradiating a surface of the substrate with radiation having a predetermined energy for a first predetermined period of time to photogenerate carriers therein; (ii) stopping the irradiation; (iii) exposing the surface of the substrate to a camera for a second…
Modular shade system with solar tracking panels
Granted: February 15, 2011
Patent Number:
7888587
A modular shade system with solar tracking panels includes a series of generally North-South oriented, spaced apart torque tubes, each torque tube having an axis, a series of panels mounted to at least some of the torque tubes to create spaced-apart rows of panels along the torque tubes, at least some of the panels being solar collector panels. The system also includes a shade structure, positioned at a selected location between selected ones of the torque tubes and above the support…
Tracking solar collector assembly
Granted: February 15, 2011
Patent Number:
7888588
A tracking solar collector assembly includes solar collector support structure, with at least one solar collector mounted thereto and first and second spaced apart pivotal support points defining a tilt axis, Southside supports, with first pivot connectors, and North side supports, with a base, a second pivot connector, and one or two support elements connected to the base and to the second pivot connector at the ends thereof. The first and second support points are pivotally connected…
Method of manufacturing solar cell
Granted: February 8, 2011
Patent Number:
7883343
A solar cell that is readily manufactured using processing techniques which are less expensive than microelectronic circuit processing. In preferred embodiments, printing techniques are utilized in selectively forming masks for use in etching of silicon oxide and diffusing dopants and in forming metal contacts to diffused regions. In a preferred embodiment, p-doped regions and n-doped regions are alternately formed in a surface of the wafer through use of masking and etching techniques.…
Trench process and structure for backside contact solar cells with polysilicon doped regions
Granted: December 14, 2010
Patent Number:
7851698
A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for…
Array of small contacts for solar cell fabrication
Granted: November 23, 2010
Patent Number:
7838062
Fabrication of a solar cell using a printed contact mask. The contact mask may include dots formed by inkjet printing. The dots may be formed in openings between dielectric layers (e.g., polyimide). Intersections of overlapping dots may form gaps that define contact regions. The spacing of the gaps may be dictated by the alignment of nozzles that dispense the dots. Using the dots as a contact mask, an underlying dielectric layer may be etched to form the contact regions through the…
Back side contact solar cell structures and fabrication processes
Granted: October 26, 2010
Patent Number:
7820475
In one embodiment, active diffusion junctions of a solar cell are formed by diffusing dopants from dopant sources selectively deposited on the back side of a wafer. The dopant sources may be selectively deposited using a printing method, for example. Multiple dopant sources may be employed to form active diffusion regions of varying doping levels. For example, three or four active diffusion regions may be fabricated to optimize the silicon/dielectric, silicon/metal, or both interfaces of…
Trench process and structure for backside contact solar cells with polysilicon doped regions
Granted: October 12, 2010
Patent Number:
7812250
A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. A trench structure separates the P-type doped region from the N-type doped region. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. The trench structure may include a textured surface for increased solar radiation collection. Among other advantages, the resulting structure increases efficiency by providing isolation between…
Modular shade system
Granted: October 5, 2010
Patent Number:
7807918
A modular shade system comprises a support structure supporting modular panels. The support structure defines a first area having a length and a width. The modular panels have upper, exposed surfaces and lower surfaces and are mounted to and supported by the support structure. The modular panels cover at least about 80% of the first area. The modular panels comprise PV panels and supplemental panels, the supplemental panels providing a feature other than shading and optionally providing…
Solar cell contact fingers and solder pad arrangement for enhanced efficiency
Granted: September 28, 2010
Patent Number:
7804022
A solar cell includes negative metal contact fingers electrically connected to N-type diffusion regions of the solar cell and positive metal contact fingers electrically connected to P-type diffusion regions of the solar cell. Both the N-type and P-type diffusion regions are on the backside of the solar cell. The solar cell includes a front side that faces the sun during normal operation. The negative and positive metal contact fingers may be interdigitated. For increased solar radiation…
Involute foil regenerator method
Granted: August 31, 2010
Patent Number:
7784184
A regenerator having a plurality of involute foils disposed in an annular gap between an inner cylindrical tube and an outer cylindrical tube. The involute shape of the foils provides uniform spacing throughout the entire regenerator and substantial surface area for fluid contact.
Preventing harmful polarization of solar cells
Granted: August 31, 2010
Patent Number:
7786375
In one embodiment, harmful solar cell polarization is prevented or minimized by providing a conductive path that bleeds charge from a front side of a solar cell to the bulk of a wafer. The conductive path may include patterned holes in a dielectric passivation layer, a conductive anti-reflective coating, or layers of conductive material formed on the top or bottom surface of an anti-reflective coating, for example. Harmful solar cell polarization may also be prevented by biasing a region…
Photovoltaic module mounting clip with integral grounding
Granted: August 24, 2010
Patent Number:
7780472
An electrically conductive mounting/grounding clip, usable with a photovoltaic (PV) assembly of the type having an electrically conductive frame, comprises an electrically conductive body. The body has a central portion and first and second spaced-apart arms extending from the central portion. Each arm has first and second outer portions with frame surface-disrupting element at the outer portions.
Ventilated photovoltaic module frame
Granted: August 17, 2010
Patent Number:
7774998
In one embodiment, a photovoltaic frame assembly comprises a photovoltaic module and a frame having a plurality of air vents. The air vents allow air to flow into the frame and thereby cool the photovoltaic module. The frame may be installed in-line with another such frame to allow air flow between frames. The air vents may be located within a perimeter of the frame to allow for structural integrity while remaining aesthetically pleasing. The frame may include an inner lip, an outer lip,…
